Automatic floor sander



Oct. l2, 1954 w. H. SCHMITT AUTOMATIC FLOOR SANDER Filed Aug. 14, 1951 JZJ l INVENTOR. ZzZZ'z'Q/yz Ecm ZZ ATTDRN EYS Patented oct. 12,1954

UNITD STATES TENT OFFICE 1 Claim.

This invention relates to oor sanding devices of the type where sandpaper, positioned against the under surface of a block is reciprocated over a floor, and in particular a block having sandpaper on the under surface carried by a horizontally disposed frame having channel shaped side members in which rollers on the sides of the block are positioned, a shaft having traction rollers thereon journaled in the frame and having a cam thereon positioned to engage rollers extended from the said block whereby the block with the sandpaper on the under surface is reciprocated as the machine is moved over a floor, and a handle extended from the frame.

The purpose of this invention is to provide a self-actuating mechanism in a frame with a block having sandpaper on the under surface extended from the frame and actuated by the mechanism as the frame travels over a floor or the like.

Various types of floor sanding machines have been provided, however, in the power actuated machine the reaction required to counteract the rotary or reciprocating motion makes it necessary to use comparatively heavy equipment and, consequently, machines of this type are not only costly to manufacture but are also costly to operate. With this thought in mind this invention contemplates a iioor sander comprising a comparatively rectangular shaped frame, the side beams of which are channel'shape in cross section providing tracks for rollers, a block having sandpaper on the under surface and rollers on the sides positioned in the frame with the rollers positioned to travel in the side beams of the frame, traction wheels journaled on a shaft extended through the frame and said shaft having a cam positioned to be rotated by the traction wheels, a yoke extended from the block and having spaced rollers therein positioned to be engaged by the cam for reciprocating the said block as the frame travels, and a handle extended from the frame.

The object of this invention is, therefore, to provide means for forming a floor sanding machine whereby a block positioned in the machine reciprocates as the machine is actuated over a floor.

Another object of the invention is to provide a sandpaper machine wherein the floor surface at the sides of a room and also in the corners thereof may be sanded.

A further object of the invention is to provide a self reciprocating sandpaper machine which is of a simple and economical construction.

With these and other objects and advantages in view the invention embodies a block having a plate with extended edges on the lower end with means for frictionally gripping a sheet of sandpaper positioned over the lower base of the plate, rollers journaled on the sides of the upper part of the block, a horizontally disposed frame having tracks in which the rollers travel and a combination of traction wheels, rollers and a cam for actuating the block.

Other features and advantages of the invention will appear from the following description taken in connection with the drawings wherein:

Figure 1 is a longitudinal section through the reciprocating oor sanding machine taken on line i -I of Fig. 2.

Figure 2 is a plan view of the machine.

Figure 3 is a cross section through the block at the forward end of the machine taken on line 3-3 of Fig. 1.

Figure 4 is a cross section through the rear part of the machine taken on line ll--4 of Fig. 1.

Referring now to the drawings wherein like reference characters denote corresponding parts the reciprocating floor sander of this invention includes a block I having a plate II secured to the under surface by bolts I2, a frame having side beams I3 and It, connected by ends I5 and I6, and traction wheels i7 and I8 mounted on a shaft I9, a cam also mounted on the shaft I9, and a yoke formed with side bars 2| and 22 in which rollers 23 and 24 are journaled and the rollers are positioned to engage the cam or sprocket 20, as illustrated in Figure 1.

The block I0 is surrounded by a shell or casing 25 and the ends are provided with recesses 26 and 2'I in which flanges of spring clips 23 and 29 are positioned whereby with the clips extended through openings and 3|, respectively, in the end walls of the casing the clips are urged against the upper surface of the edges of the base plate II by springs 32 and 33. The springs are retained in the recesses by plates 34 and 35 and these plates are secured in position by screws 36.

Rollers 3l, which are journaled by pins 38 in openings 39 in the sides of the block, are positioned in beams I3 and i4' and shown in Fig. 3. The beams are channel shaped in cross section, being provided with upper and lower flanges 40 and 4l on the beam I3 and 42 and 43 on the beam I4.

The bars 2| and 22, forming the yoke, which extend from the end of the frame or casing of the block, extend on the sides of the cam 20 and the rollers 23 and 24 are journaled in the extended ends by pins 44 and 45.

The traction wheels I1 and I8, which are provided with hubs 4B and 41, repectively are iixedly mounted on the shaft i9 and as the shaft is rotated by the wheels traveling over a iioor, or the like the shaft rotates the cam 20 and forces the rollers 23 an d 24 forwardly and backwardly, thereby reciprocating the block and the sandpaper, as indicated by the numeral 48, thereon.

The sander is provided with a handle 49 which is positioned at the upper end of the rod 50 and the rod is mounted on a yoke having side arms 5I and 52 that are connected at the upper end, by a cross rod 53.

With the parts arranged in this manner forward or backward movement of the sander causes rotation of the traction wheels H and I8 whereby the cam is operated to move the block l0 forwardly and backwardly thereby with the sandpaper positioned on the floor the iioor is sanded with a reciprocating motion of the sandpaper.

By this means with the edges of the sandpaper mounting extended beyond the sides of the frame the .floor may be sanded up to the walls and also in the corners.

It will be understood that modifications may be made in the design and arrangement of the parts without departing from the spirit of the invention.

What is claimed is:

An automatic floor sander, comprising a frame embodying a pair of spaced parallel horizontally disposed side beams, a pair of spaced parallel end pieces extending transversely `bem/'een said side beams and connected thereto, a .shaft positioned between said pair of end pieces and supported by said beams, a pair of spaced parallel traction wheels mounted on said shaft, a cam interposed between said pair of traction wheels and mounted on said shaft, said cam being provided with a plurality of recesses in its outer periphery, a yoke including a pair of side bars, each of said side bars including a iirst pair of straight portions arranged in spaced parallel relation with respect to each other, said straight portions being interposed between said pair of traction wheels, an odset section extending outwardly from each of said straight portions, and a straight section extending froin each of said offset sections, said straight sections being arranged in spaced parallel relation with respect to each other, a block reciprocably mounted between the beams of said frame and journaled therein, a plate secured to the bottom of said block, a sheet of sandpaper extending across the lower surface of said plate, spring pressed clips for maintaining said sheet of sandpaper connected to said plate, the straight sections of said side bars being connected to said block, a pair of rollers journaled in the straight portions of said side bars for engagement with said cam, said rollers being of less diameter than said traction wheels, side arms connected to said frame, a rod extending upwardly from said side arms, and a handle mounted on said rod.

References Cited in the iile of this patent UNITED STATES PATENTS Number Name Date 906,069 Seferian Dec. 8, 1908 1,195,428 Williams Aug. 22, 1916 1,483,012 Reineke Feb. 5, 1924 1,635,480 Jacobson July 12, 1927 1,668,966 Kirwin et al, May 8, 1928 1,861,940 Roos et al June 7, 1932 2,393,089 Crosby Jan. 15, 1946 2,464,296 Ekstrom Mar. 15, 1949 2,477,807 Johnson Aug. 2, 1949 2,564,490 Marr et al Aug. 14, 1951 

